Using MgSO4 or MgCl2 to fight byropsis
- Thread starter rhouse24
- Start date
HighlandReefer
Team RC
Not that I am aware of. 
It seems that Tech M works well from hobbyists' reports. Why, we really don't know.
It seems that Tech M works well from hobbyists' reports. Why, we really don't know.
HighlandReefer
Team RC
You can try it and see what results you get. You would be driving up your sulfate level substancially. I don't know what form Tech M uses, they could use the sulfate form.
disc1
-RT * ln(k)
You add 4ppm of sulfate for every 1ppm of magnesium using mag sulfate.
SO to go from 1350 to 1600 (a 250ppm rise in mag) you would be getting a 1000ppm rise in sulfate. Seawater is 2700ppm sulfate. So you're going to increase the sulfate in the tank by 37%.
I would use magnesium chloride or a mixture of mag chloride and mag sulfate.
SO to go from 1350 to 1600 (a 250ppm rise in mag) you would be getting a 1000ppm rise in sulfate. Seawater is 2700ppm sulfate. So you're going to increase the sulfate in the tank by 37%.
I would use magnesium chloride or a mixture of mag chloride and mag sulfate.
HighlandReefer
Team RC
Perhaps its the sulfates that kills the algae and not heavy metal contaminates. It would be interesting to know what is in the Tech M mag supplement. 
Thanks for the calculations David. Mag sulfate does drive up sulfate levels quite high. :lol:
Thanks for the calculations David. Mag sulfate does drive up sulfate levels quite high. :lol:
HighlandReefer
Team RC
FWIW, some hobbists that used Randy's mag solution (a mixture of mag sulfate and mag chloride - more mag chloride), it did not kill bryopsis. 
HighlandReefer
Team RC
I have looked for the effects of increased sulfate levels on coral and micro-organsims. It seems a moderate increase increases growth. I have not seen the effect of large increases like we are talking about.
rhouse24
New member
Good point, how about a 22% increase which would be the same as raising the mag to 1600ppm using the recommended 3:5 ratio. But instead I would just use MgSO4 and only take mag to.... 1500ppm.
disc1
-RT * ln(k)
The math doesn't quite work that way. That 3:5 is a volume ratio and has nothing to do with the molar ratio we are looking for. I'll have to look in the article to remember the actual numbers but it's down right now. Giving a 404 error. So I'll have to get back to you on this one.
Kent tech M per the manufacturer is "ionicaly balanced" and contains "magnesium chloirde and magnesium sulfate". These are present in seawater at 19,350ppm chloride and 2700ppm sulfate. Kent doesn't give the exact ratio they use but why would they balance it other than to usual ratios and claim ionic balance? So I doubt the sulfate would have anything to do with the bryopsis effect claimed unique to Tech M. If it were the sulfate folks would be seeing this with Seachem's product which is mostly epsom salt. I don't know of any reason the extra sulfate would uniquely limit macro algae Most speculate it's an impurity unique to Tech M. I don't personally favor the mag vs bryopsis technique and remain skeptical.
BTW raising the magnesium will also raise the salinity/ specific gravity so watch that if you raise it a lot. 100ppm raise in mag raises salinity 0.4ppt (eg 35ppt to 35.4 ppt )
BTW raising the magnesium will also raise the salinity/ specific gravity so watch that if you raise it a lot. 100ppm raise in mag raises salinity 0.4ppt (eg 35ppt to 35.4 ppt )
HighlandReefer
Team RC
Thanks for the info Tom.
Back to the heavy metal theory.
Back to the heavy metal theory.
Here's a reach on why it may happen. Maybe David can tear into this late night idea since it's just speculation on my part.
The extra magnesium could increase the levels of carbonate alk by slowing precipitation(allowing greater saturation) thus leaving a bit more carbonate to take up more H+ for shifts to bicarbonate. In turn less available H+ in the water( higher ph) could shift the PO4,HPO4, H2PO4,H3PO4 to the left perhaps strengthening the bond to calcium carbonate surfaces like live rock reducing any leaching that may be occuring and feeding the bryopsis. The increase in specific gravity from the mag additions might play a role as well.
The extra magnesium could increase the levels of carbonate alk by slowing precipitation(allowing greater saturation) thus leaving a bit more carbonate to take up more H+ for shifts to bicarbonate. In turn less available H+ in the water( higher ph) could shift the PO4,HPO4, H2PO4,H3PO4 to the left perhaps strengthening the bond to calcium carbonate surfaces like live rock reducing any leaching that may be occuring and feeding the bryopsis. The increase in specific gravity from the mag additions might play a role as well.
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